1. Field of the Invention
The present invention relates to ignition systems, and in particular to an improved ignition system for variable ignition timing.
2. Description of the Related Art
Sophisticated, high-priced engines in vehicular or stationary application generally use the principle of variable ignition timing. Variable ignition timing provides the easiest possible starting for the engine (retarded timing) and the most efficient high-speed engine operation (advanced timing). On most vehicles, for many years, the timing adjustment was handled by a distributor which used either centrifugal weights or the engine vacuum to vary the timing. In recent years, many vehicle and stationary engines have used computerized distributor-less ignitions. Such distributor-less ignitions use inputs from engine speed and load sensors to electronically vary the timing of ignition coil firing.
Single cylinder engines cannot use a distributor and have, for economic reasons, not been known to be equipped with computer-controlled ignitions except in laboratory settings. Instead, these engines are equipped with either magneto or inductive ignitions which use a fixed ignition timing set somewhere between ideal startup timing and ideal running timing. Additionally, the same economics have dictated that the ignitions used be comparatively low power with limited spark energy. Moderately hard starting, occasional misfires and less than optimum engine efficiency have had to be tolerated as reflecting the best technology reasonably available. These shortcomings have been particularly apparent in engines run on gaseous fuels. The far higher voltage demand of gaseous fuels have rendered gaseous fuel unusable in some engines.
Accordingly, there is a need for a small engine ignition system with a high-energy spark as well as multi-sparking. There is a still further need for a small engine ignition system which provides for complete ignition of the air fuel mixture and resulting in both the absence of misfires and greatly improved engine efficiency.